10 And I would, my brethren, that ye should know that all the kindreds of the earth cannot be blessed unless he shall make bare his arm in the eyes of the nations.11 Wherefore, the Lord God will proceed to make bare his arm in the eyes of all the nations, in bringing about his covenants and his gospel unto those who are of the house of Israel. (1 Nephi 22:10-11)
When it speaks of the Lord making bare His arm in the eyes of all the nations, it means that the Lord will make His power obvious.
Making bare an arm is a great image to describe how someone shows their power. We visualize a strong man rolling up their sleeves and flexing their muscles and maybe doing some heavy lifting to emphasize the strength they have.
When the Lord makes His arm bare, or shows His power, it will be done through the power of the Holy Ghost that will work upon the hearts of men when they hear the truth of the gospel. It will attract those of the house of Israel to the covenants of the Lord. When they enter covenants, they will also experience the power of the Lord through the priesthood and receive blessings promised to Abraham and his seed.
What “heavy lifting” does the Lord do that we can see? He changes people’s lives. The older we get, the more we understand how difficult change can be without God. People are stubborn. Habit is a deep rut to get out of. But God has the power to change lives, and He shows that to everyone, one by one. He shows people through the Spirit a hint of how they could be blessed, and then they get to choose to respond or not.
Also, everyone will see the power of God at the resurrection.